The seat is poised to become open when Republican Rep. Jo Anne Emerson's resignation becomes official.

Democratic Gov. Jay Nixon will call a special election once that happens. The district's party committees will choose their nominees — there will be no primary special election.

The 8th District is a safe Republican seat, but Democrats wasted no time in sniping at Kinder, who faced a rather unique scandal in 2011 involving a photograph of him with a woman at a bar that promoted pantless parties.

"After the dysfunction of the last few weeks in the Republican Congress, the next step is no surprise: having Pants Party Pete as their standard bearer," said Jesse Ferguson, communications director for the Democratic Congressional Campaign Committee.

Another top contender for the seat is Lloyd Smith, executive director of the state Republican Party. Insiders say Kinder has the edge, but not an insurmountable one.

"I still think it's Peter, but it could be a little rocky," one Missouri GOP insider said, noting that Smith would put up a tough fight.

As for the pants party attack, the insider said the committee members were unlikely to be moved by reminders of that story. "In his home county, they know that he's a single guy who has dated lots of women and they don't care," the source said.